It's amazing how many from the USA insist that the inner diversity in the USA is comparable to the one in Europe. I've heard this many times, namely here in HN. It is not comparable. PERIOD.
Even if the poster goes a bit to the extreme of bringing Russia in to the conversation, even inside the EU, there is still no comparison on how how diverse Europe is (e.g. Portugal to Norway, Greece to France, Spain to Germany) compared to the USA. Some countries, like Austria and Germany do have some similarities, but - to the untrained eye - Canada and the USA will seem relatively similar also, when compared to Mexico!
Perhaps the diversity of the USA is not the extreme of Europe, but I would be quick to point out that the regional differences in the US are quite notable even to an outside observer.
There are 5 major regions of the US: Northeast, Southeast, Midwest, Southwest, and West. Each of these regions has noted differences in: dialect, culture, food, general behavior, economy, and quality of life.
Now regardless of US or Europe we have to factor in the population density of a location. It's no secret that urban culture is very different from rural culture be it in Oregon or in France.
Granted: we mostly speak the same language, we all share a common currency, and we all answer to the same federal body which represents us.
There is more diversity in Europe, that much I am sure of. But there is no problem with a comparison of the two.
If you focus on 'diversity', you miss the bigger picture, because of course every place is unique. The US has for example far more pronounced extremes of urban vs rural (which many too forget). The real issue is distance, and how Europeans and Americans in general have vastly different concepts of what's far.
If you're in the US or Canada, driving for 10 hours means you're going to visit your aunt. Doing the same anywhere in Europe means you're likely 2 countries over, and it becomes a 'huge trip' in people's heads. Heck, I know several people who have driven more than halfway across Canada, in Europe no-one who drove e.g. from Paris to Istanbul.
And while the European market is supposedly unified, in practice there are significant variations in pricing and availability as soon as you cross a border, simply because that's something few people do. And of course the language difference means most local media is opaque to outsiders.
So I would say that the US is definitely diverse, but it's a gradual diversity, that transitions smoothly from ultra-urban to no-one-for-miles rural. It works on very large distances, and is mediated by a shared media, politics and language. European countries meanwhile are much more homogenous on the inside, but there are a lot of forces keeping each one unique.
Why drive that distance when there are decent trains or, much more common these days, excellent low cost airlines? [Pretty common for people to fly for 4+ hours to go on vacation from the UK to Turkey].
Heck, I know several people who have driven more than halfway across Canada, in Europe no-one who drove e.g. from Paris to Istanbul.
Abstract away the vast distances of road and think of it as nodes on a directed graph. How many nodes (ie: inhabited locations of distinct identity) did you pass through from source to destination? That's a kind sociocultural or even ecological distance you traveled, and it can actually be larger on a Paris-Istanbul trip than on a cross-Canadian trip.
I was actually saying "Paris-Istanbul is more diverse than cross-Canada". North America has large distances between "significant nodes" on the map, Europe/Asia has smaller distances.
So you replied in agreement with a tortured graph theory analogy devoid of concrete ties to reality? I'm confused. Usually when people say "actually" they are correcting someone.
There are many more such regions in Poland, for example - I have no time at the moment to look up their translations, but we have, among others: Mazowsze, Slask, Pomorze, Lubelszczyzna, Warmia i Mazury. That's five, too. And each of these regions has noted differences in: dialect (to the point of using language completely incomprehensible to others, which at least three(!) of this regions do), culture, food, general behavior, economy, and quality of life.
These differences between regions inside one country is exactly what is comparable to differences between Midwest and Northeast.
Now think about the fact that Europe consists of tens of countries, many of which are significantly more diverse internally than Poland. And try to compare this monstrous complexity to differences between USA regions.
For me it seems to be daunting and impossible task because of huge difference in scale, yet you have no problem with it. I can only admire your courage :)
Another aspect we should factor is history. Countries in Europe are in general much older than the USA. That is probably one of the biggest reasons for such rich diversity in Europe. Portugal has the same borders since 1249; Greece exists since the classical age; etc.
That is why I think that despite existing notable differences between those regions of the USA, they are on a different scale. Dialect, culture, food, general behavior, economy and (even) quality of life, of each country is affected by it's history.
You can compare Europe to the US, but you are comparing a diverse geographical area to a nation state. Apples to Oranges. It's like comparing the US to Asia.
Even if the poster goes a bit to the extreme of bringing Russia in to the conversation, even inside the EU, there is still no comparison on how how diverse Europe is (e.g. Portugal to Norway, Greece to France, Spain to Germany) compared to the USA. Some countries, like Austria and Germany do have some similarities, but - to the untrained eye - Canada and the USA will seem relatively similar also, when compared to Mexico!